Posted:30th Oct 2003I have also seen the Northern Lights. One morning at about 1am, after we had come back from the pub, my shepherdess friend Karen and myself we're having a smoke and a can of Fosters in the barn, keeping the little hand fed lambs company, when Lionel (another shepherd) came in and told us to go outside. Stood and watched for about 20 mins, the lights dancing in the sky.

Posted:31st Oct 2003I wanna see stuuuufff. Vanize, do you know what the craic is with this w/e? It says on CNN that there'll be more saterday and sunday. So there must be something happening this w/e. Do you have to be a certain bit north or somethings...

Not that I'm going to do any more than tell you to go to a link about auroras and one about coronal mass ejections (CMEs) and tell you that the aurora happening now is due to several large CMEs from the sun blasting the living daylights (or in the case of aurora, nightlights) out of the the Earth's magnetosphere. This is one of the more visible effects of space weather.

If you want to know more, please feel free to PM me any questions - studying this is what I do for a living and I'm always happy to talk about it.

Posted:31st Oct 2003ahh, Jafar, you snuck that question in while I was typing!

The sun is at a particularly active time period right now, having just past what is called "solar maximum". Solar maximum is defined as a period where the sun becomes more active. there are more sunspots, more solar flares, and more coronal mass ejections, all of which affect the magnetic and electric enviroment around the earth. When a CME hits the earth's fields in just the right way and with enough strength, it can trigger the enviroment around the earth to release a lot of energy that it as stored in the form of charged particles and magnetic field tension. you can think of the previous like a battery and the latter like a tightly wound and greatly stretched rubber band. if you put extra force on this storage system, you can in effect break that rubber band, causing the magnetic fields to 'snap' and recoil. the charged particles, which are bound to these magnetic field, then wind up being greatly accerated/energized. a moving charged particles is a current. So in a way, the impact of the CME on the earth's magnetic field and the snapping of those lines sort of short circuts the battery - and it is a frigging huge battery!

The entire system we are talking about is 10s of thousands of times the volume of the earth itself, extending 10 times the radius of the earth in the direction of the sun, about 20 times the earth's radius on the flanks, and approxmiately 200 times the earth's radius away from the sun. like i said - BIG!

So take all that stored energy and run a current right down the field lines towards earth - meaning you suddenly get lots of charged particles impinging on the upper atmosphere. When an charged particle runs into a neutral oxygen atom and gives it a good whack, it excites the electrons in the oxygen atom to an excited state. when this state decays back to the ground state, you get a green glow (or red) as it gives off the excess energy it temporarily stored in that excited electron. Same for nitrogen, but that will often give off purple. throw in some other constituant elements of the atmosphere, and you can get many colors.

Since these charged particles are flowing down field lines, the effect is the create verticle curtains of color. The ripples and waves you see in these curtains are actually the shapes of the field lines changing and the winds in the extreme upper atmoshpere blowing around those glowing neutral atoms.

Because of the orientation of the earth's magnetic field, you must be relativly close to one of the magnetic poles to see the really nice aurora. They rarely come down past 50 degrees latitude. Every so often, about once every 11 years or so, you can see a dull red aurora as close to the equator as 30 degrees latitude, but these tend to be very dim and easily washed out by city lights or moonlight.

Posted:31st Oct 2003BTW, those pulses you see in the aurora are not your imagination - it is a manifestation of the variability of the solar storm hitting the earth and magnetic field dynamics happening many 10s of thousands of kilometers away!

Posted:31st Oct 2003One last thing - the reason we can predict this stuff coming now (how we can predict space weather), is due to a large network of satellites orbiting around the earth and hoving at the LaGrange point between teh earth and sun.

the LeGrange point I'm refering to is the point in space where the gravitation pull of the sun and that of the earth are balanced. you can keep things on station here easily with only a minimum amount of energy, and they just seem to magically always keep the same orientation between the earth and sun.

The SOHO observatory is here and is one of the most amazing and succesful space satellite missions ever. We have learned increadble things from it. go to the link I just mentioned to see actual movies of coronal mas ejections blowing off of the sun (very cool stuff, especially when you realize that the earth is smaller than a single picture in any of the pictures of movie farmes on that page!). ecause of SOHO, we can see when the sun aims a CME directly at us, and we get a couple days warning. This can be hugely important to the communication industry, who rely on satellites in geosynchonous orbit that are vulnerable to space weather affects. The military to of course. And beleive it or not, pawer cmopanies and even oil companies (anyone who has long length of conductors such as power cables and pipelines) since geomagnetic storms caused by CME impacts can induce huge currents on such things, causing relays to blow out, pipe fitting to prematurely corrode, and all sort of stuff.

Posted:31st Oct 2003I got to watch them with my lil sister last night who had never seen them before! It was so good to share them with her! I used to live in northern Michigan so I was blessed and saw them constantly. I was planning on spinning last night but the lights were no competition. I just watched in awe as usual.

love & light,cage

Without further guilding the lily and with no more ado, I bid you farewell and sweet dreams...

Posted:31st Oct 2003I saw them to tonight. the power flickered here and I figured it was because of the solar flare's I heard about. I decided on a whim to go out and look to see if I could see the northern lights (Ive seen them a couple of times before but they were only very faint almost invisible bands of light in the sky) This time it was like a big web of bright colour changeing bands. Most insane thing ever. They slowly changed from red to green to white.

Im only in nova scotia canada, I can't imagine how amazing they would be tonight if you were up in the arctic. Ive read about how they get so strong sometimes that you can hear them (it's actually your brain picking up the magnetic fields and registering it as sound)

Posted:31st Oct 2003Wow, thanks vaneeze, i thought i was pretty clued up on northern lights, but now my head is somewhat swimming in a gravitational feald thousands of miles across, looks pretty but.....

Posted:1st Nov 2003over here in the states, like on NPR art bell's old radio show, there are many saying that the current unprecedented solar activity is due to a previously "unknown," massive, highly magnetic body entering our solar system, and that the mass will greatly affect our magnetic stasis throughout the solar system. polar shift for breakfast anyone? ice age comin

-Such a price the gods exact for song: to become what we sing-Seek freedom and become captive of your desires. Seek discipline and find your liberty.-When the center of the storm does not move, you are in its path.

Posted:1st Nov 2003ACtually, this solar cycle was double peaked, which is not unusual, and the last peak was only 1.5 years ago. Furthermore, it takes a while for things to ramp down from solar maximum conditions. In fact, the solar cycle is basically sinusoidal, so the sun onl really spend a little more time in "quite time" conditions in the course of one 11 year cycle.

There are also longer time period cycles, where the strength and severity of the 11 year solar cycles vary. occasionally, the solar cycle dissapears completly (e.g. the "maunder minimum" of the 1600s). Currently, we seem to be at or approaching a peak of this longer time range cycle, such that even our "solar minimum" conditions are more active than the solar maximum conditions in certain area in the recorded past (humans have actually been studying the solar cycle for well over 500 years).

Posted:2nd Nov 2003vanize, you're like the walking cure for all my naive left wing ignorances can i interest you in a slice of unfounded paranoic cataclysm for breakfast?

-Such a price the gods exact for song: to become what we sing-Seek freedom and become captive of your desires. Seek discipline and find your liberty.-When the center of the storm does not move, you are in its path.